Living organisms, such as animals, in particular mice or rats, are used extensively as human models in the research of drug development; genetic functions; toxicology research; understanding and treatment of diseases; and other research applications. Despite the differing lifestyles of humans and animals their extensive genetic and neuron-anatomical homologies give rise to a wide variety of behavioral processes that are widely conserved between species. Exploration of these shared brain functions will shed light on fundamental elements of human behavioral regulation. Therefore, many behavioral experiments have been designed for mice and rats to explore their behaviors. This research includes, for example, experiments studying home cage behaviors of lab animals, freezing experiments for conditioned fear, self-administration in operant chamber, social interaction experiments in an open environment, open field locomotion experiments, object recognition experiments, a variety of maze experiments, water maze experiments, forced swimming and tail suspension for depression studies and others. The use of these and other types of experimental paradigms were previously described in literature, for instance in the U.S. Patent Application Publication No. 2004/0141635 to Liang, which is hereby incorporated by reference in its entirety.
Many of these experiments are best observed by recording animals in specified periods of time including several 24-hour periods and subsequently using two independent observers to score the recording. However, the drawbacks of such observations include the instability of long term human observation, the time consumed, and the huge costs associated with the observation.
Social behavior is the basis of one of the most generally accepted independent dimensions of personality and has many important roles in the survival of individuals and the species. Many clinical disorders associated with social behavior include difficulties in creating or maintaining social interactions, such as social anxiety disorder, several personality disorders, autism, etc. Social interaction tests are typically designed for evaluating behavior parameters of social communications, including analyses of pair-bonding, dominance hierarchies, social memory, social deficits, social phobias, social anxiety, joyful play, aggression and flight, maternal and sexual behaviors. Home cages, basic chambers or open field and other test environments are presently commonly used with two or more animals to perform social behavior experiments. As with the other types of behavior analysis, these experiments are usually conducted by recording the animals for a predetermined period of time in a particular environment followed by subsequent review by two independent observers. Among the social behaviors that are identified by the observers include pouncing, social grooming, crawling, pinning, sniffing, following, mounting, etc.
Typically these experiments use human observation of the recordings of the sessions. Given the tediousness of the work and the difficulty of being able to observe accurately the position and interaction of the animals by human observation, this type of analysis can result in inaccuracy and inherently includes subjective analysis. For example if the human observer is only looking at one view the activity may be hidden by the position of one of the animals. If the observer is looking at multiple views, it is very time consuming and difficult to view two or more views simultaneously. Given the fact that this method is labor-intensive, the analysis is costly.
Video analysis technology has been applied in behavior analysis in objects including animals and human in an effort to alleviate some of these problems. An automated lab animal home cage behavior is described in U.S. Patent Application Publication No. 2004/0141635 to Liang, which is hereby incorporated by reference in its entirety. The SocialScanTop product from Clever Sys Inc utilizes one top view camera to analyze social interactions of multiple animals. However, this product and others using a single camera fail to meet the demand by scientists in the field.
Thus, there exists a need for systems and software that can address the problems of measurement and analysis in the experiments mentioned above, provide analysis of meaningful complex behaviors to meet the post-genomic era's demands, and obtain consistent results.